Vitamin D: Modulator of the Immune System

Curr Opin Pharmacol. 2010 Aug;10(4):482-96. doi: 10.1016/j.coph.2010.04.001. Epub 2010 Apr 27.

Abstract

1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), the active form of vitamin D, is known to regulate calcium and phosphorus metabolism, thus being a key-player in bone-formation. However 1,25(OH)(2)D(3) also has a physiological role beyond its well-known role in skeletal homeostasis. Here, we describe 1,25(OH)(2)D(3) as an immunomodulator targeting various immune cells, including monocytes, macrophages, dendritic cells (DCs), as well as T-lymphocytes and B-lymphocytes, hence modulating both innate and adaptive immune responses. Besides being targets, immune cells express vitamin D-activating enzymes, allowing local conversion of inactive vitamin D into 1,25(OH)(2)D(3) within the immune system. Taken together, these data indicate that 1,25(OH)(2)D(3) plays a role in maintenance of immune homeostasis. Several epidemiological studies have linked inadequate vitamin D levels to a higher susceptibility of immune-mediated disorders, including chronic infections and autoimmune diseases. This review will discuss the complex immune-regulatory effects of 1,25(OH)(2)D(3) on immune cells as well as its role in infectious and autoimmune diseases, more in particular in tuberculosis and type 1 diabetes (T1D).

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adaptive Immunity / physiology
  • Autoimmune Diseases / immunology
  • Calcitriol / deficiency
  • Calcitriol / physiology*
  • Calcitriol / therapeutic use
  • Communicable Diseases / immunology
  • Diabetes Mellitus, Type 1 / immunology
  • Diabetes Mellitus, Type 1 / prevention & control
  • Humans
  • Immune System / physiology*
  • Immunity, Innate / physiology
  • Receptors, Calcitriol / agonists
  • Signal Transduction
  • T-Lymphocytes / immunology
  • Tuberculosis, Pulmonary / drug therapy
  • Tuberculosis, Pulmonary / immunology
  • Vitamins / physiology*
  • Vitamins / therapeutic use

Substances

  • Receptors, Calcitriol
  • Vitamins
  • Calcitriol